There are two separate cases for a MATLAB upgrade:
1) Installing a new general release version of MATLAB.
2) Installing a web update to a MATLAB version (also know as a plus '+' release).
General Release Upgrade
When you install a new version of the general release, you will simply install the new version of MATLAB into a new folder. The installer will not overwrite any other versions that are already installed. If you have a network installation of MATLAB, the network license manager will need to be updated before you can run the new version of MATLAB.
For the complete instructions on how to install MATLAB, please refer to the installation guide here:
Install Products
Once the new version is installed, you can remove the previous installation of MATLAB, or leave it installed if you wish.
NOTE: When uninstalling, if you are prompted to deactivate, do not do so. Deactivation will also remove your license for the new release.
Plus Release Upgrade
If you are upgrading from a standard release to a plus (+) release (e.g. upgrading R2006b to R2006b+), you will need the installation files only for the products that have updates. The plus releases are only available through downloads. Once you have downloaded all of the updated files, launch the installer that was downloaded with the plus release files. For more information about this installation process, see the related solution: "How do I install additional toolboxes into an existing installation of MATLAB?"
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